Combined seaming and pinking mechanism



March 26, 1946. M. POPPER I 2,397,431

COMBINED SEAMING AND PINKING MECHANISM v Filed Deb. 2a, 1942 I 3Sheets-Sheet 1 11111611101: MAX POP/DER March 26, 1946.

Fild Dec. 28. 1942 M. POPPER COMBINED SEAMING AND PINKING MECHANISM I 3Sheets-Sheet 2 MAX POPPER March 26, 1946.

M. POPPER COMBINED SEAMING AND PINKING MECHANISM 3 Sheets-ShedtS FiledDec. 28, 1942 Patented Mar. 26, 1946 COIWBINED SEALIING AND PINKINGMECHANISM Max Popper, Brooklyn,.N. Y., assignor to Lewis InvisibleStitch Machine Company, St. Louis, Mo., a corporation of MaineApplication December 28, 1942, Serial No. 470,357

1 Claim.

The invention herein disclosed relates to a pinking mechanism adapted tobe mounted on a sewing machine and operated in timed relation withrespect to the stitch-forming mechanism. More particularly, theinvention relates to a pink ing mechanism of the kind known as a choppertype in Which co-operating, relatively movable V-shaped knives partakeofa relative, substantially reciprocatory movement.

An object of the invention is to provide a pinking mechanism of thiskind that is substantially complete as a unit. Another object of theinvention is to provide a mechanism of this kind in which theco-operating knives are urged into pressure contact as the knivesapproach cutting relation and in which the pressure is relieved as theknives move away from cutting relation. A further object of theinvention is to provide a mechanism of this kind in which substantiallyall of the operating mechanism is enclosed. Another object of theinvention is to provide a mechanism of this kind that is compact, simplein construction, comparatively inexpensive to manufacture and reliablein operation.

The foregoing objects and certain advantages that will hereinafterappear are realized in the embodiment of the invention illustrated inthe drawings and described in detail below. The drawings include:

Fig. 1 which is a side elevation of a sewing machine with a pinkingattachment thereon;

Fig. 2 which is an enlarged fragmentary elevation, partly in section;

Fig. 3 which is a section taken on the line 33 of Fi 2; r

Fig. 4 which is a plan of the pinking mechanism;

Fig. 5 which is a side elevation of the same;

Fig. 6 which is a' bottom plan of the same;

Fig. 7 which is a sectional elevation taken on the line 1-1 of Fig. 4;and

Fig. 8 which is a front end elevation of the same.

Th sewin machine illustrated in the drawings, is a standard sewingmachine, more particularly, it is a machine known in the trade as aSinger 400. This machine includes a frame which consists of a base I, astandard 2, extending from the base at one end thereof, and anoverhangingarm 3 extending from the upper end of the standard, over andparallel to the base. On the end of the arm 3, there is a head 4 inwhich the needle bar 5 is reciprocally mounted. The needle bar carries aneedle 6. The machine illustrated is a two-thread or lockthe ledgerblade l8,

stitch machine having a rotary hook and bobbin below the base (notshown) cooperating'with the needle. The usual thread-handling mechanism(not shown) is also provided for effecting a series of stitches as themachine is operated.

In the arm 3, there is journaled a main shaft 1 through which thestitch-forming mechanism of the sewing machine is actuated. The shaft 1extends through the end of the arm: at the standard. On the extended endof the shaft '1, there is mounted a pulley 8. Through this pulley themain shaft of the sewing machine is driven by an electric motor (notshown) in the usual manner. r

On the base I of the sewing machine, there is mounted a pinkingmechanism that includes a frame 9 secured as by bolts to the base. --Thepinking mechanism illustrated isof the kind known as the chopper type.It includes a ledger blade l0 substantially parallel to the; base andhaving a V-shaped opening forming cutting edges and a male V-shapedknife ll positioned and arranged to co-operate with the ledger blade.The male knife is mounted on a male knife carrier l2 that is pivotallysecured to one endlof a lever l3. The lever I3 is pivotally mountedbetween its ends in the frame 9 and extends through the end of the frame9. Oscillation of the lever [3 effects substantially reciprocatorymovement of the male knife H with respect to For the purpose ofeffecting pivotal movement of the lever l3, a drive mechanism isprovided. This drivemechanism is driven from the main shaft of thesewing machine. To this end, a spur gear i4 is secured on the main shaftl of the sewing machine for rotation therewith. .A bracket l5 supportsthe driving mechanism through which the pinking mechanismis actu ated.

The bracket l5 extends up from the'base Within the standard 3. It'isprovided with a flat end section l6 that is secured to one face of abearing lug I! formed on and extending from the base I. The bearin lugI! is provided on the machine as a bearing for a shaft 18 through whichthe rotary hook of the stitch-forming mechanism is driven. Counter-sunkmachine screws l9 secur the fiat end section l6 of the bracket i5 to thebearing lug H. The, opposite end of the bracket l5 includes a pair-ofaxially alined, spaced bearings 20 and 2!. In these bearings a driveshaft 22 is journaled. The drive shaft carries a gear 23 secured thereonfor rotation therewith. Extending from the bearing With thisarrangement, the gears; I4, 21 and 23 constitute a reduction gear trainmounted for movement, about a pivot 46, extend-- for driving the shaft22 at a lower speedthan{ the shaft I. For driving pinking mechanisms ofthe type illustrated, this reduction. may desirably be eithertwo to oneor three 130 0118."

A The shaft 22 extends through the bearing 21;

which extends, slightly, through ancpening in the wall of the standard8'. OIithis extended end of the shaft there is secured a collar 29-11am-.a crank pin 30 extending therefrom. The crank: lpir 3D; has a ballformed" therein which is received in "a complementary socket 3i} securedon one end, ofa connecting-rod 32. On the'op posite end ofthe-connectingrod- 3 2, there is secured alikesocket 3'3.' This latter socket receivesa; ball formed on a pin 34 secured in and extendingfromthe end of thelever l3.

With thisarrangem'ent; the drive; shaft 22 is drilzen', in a. constant;ratio and in timed relation with respect to the main shaft! of thesewing machine; and in consequence with respect to the stitch formingmechanism. Through thecrank 29and-the'connecting rod 3-2, the lever iiiof the pinking mechanism is oscil1ated. The relation is sutcli that-the,male knife enters theledger blade to, efi'e'cfi a cut on thedownward-stroke of the needle, while the material acted on isstationary. The movements ofthe, maleknife are, of course, less:ing'num'b'er than the-'reciprocations of the edle.

The: pinking' mechanism is illustrated indetail inFigsfl to 7 inclusive.In this pinking mechanismgthe actuating lever I3 is housed within the;frame '9,extendi-ng therefrom at the ends thereof. The lever is'rnountedto oscillate about a, pivot pin 35 extending between the walls of theslot 36' within which the lever is mounted and extendingq through abearing lug 31 formed on theleverr V The frame has" side flanges 38 onoppositesides thereof through which it is boltedto the base ofagsewingmachin'e. For this purposeholt slots 39lare provided through the fiange.The frame also hasa, front extension orflangeid to which the,- ledgerblade H1 is secured-asgby machine screwsr4'l'i Also secured onthe-extension d5, by a thumhiscrew 42:, there' is a cloth or edge guide43 which-servesto guide the-edge of the cloth inpassing'throughthemechanism.

The forward end 44 of the frame 9 through which the lever 13* extendsis; curved-manarc about the axis of the pivot 35. The correspond-v ing,endof the lever 13, that portion outside of the'frame' this" of-greaterthickness thanthe remainder of" the leverand it is bifurcated; to'formspaced arms, 45*. The edges, extending on either of. the lever l3? ridealong the curved surface 44' e of the frame 9 when the lever isoscillated. The

bifurcation of the end of the lever provides a slot in the top of thelever, the arms 45 extending above the lever proper.

Between the arms 45 of the lever l3, the knife carrier I2 is pivotallymounted. This knife carrieris inthe form of aibellcrank lever and it ising betweenthe arms 45. To one arm 41 of the knife carrier, the maleknife I I is secured by a bolt 48. The other arm d9 of the bell cranklever hasa-ia. reduced extension 49a extending into the frame 9. To thearm 45, one end of a leaf sprin 50-, is secured. The leaf spring extendsinto the frame. and itis, engaged by an adjustable abutmentz pin5lthreaded into the top of the frame 9. The spring 50 serves to provide ayieldable force in a direction to move the knife holder aboutthe pivot.The male knife, even when out of the ledger blade is restrained frommovement away from. registering relation wi-th the ledger bladeby guidelugs 52 extending from theledg'er blade. Thusthe spring serves to effecta. pres-- sure engagement of the: edges ofthe male :and female'knives asthe male knife: moves into the female knife. This pressure is exertedina di rection substantially'parallel; to the cutting-plane and in- 'adirection towards the apex of the cutting edges. By locatingthexabutment pin-5| (Fig; 7;) in the relation illustrated with respectto the pivot ild, the spring pressure increases as the male knife movesdownwardly into cutting: relae tion with. the ledger blade and itisrelieved when the male knife withdraws: to the-positionillus-. trated.Thisxis a desirable relation: asit sub-L stantially reduces the wear onthe knives, particu-la-rly' the cutting edges.

From the f ingdewri tion Of the-com bined seaming and pinkingmechanismillustrated in the-drawings, it will be seen that Joy. this in ventionthereis provided a simplified pinking mechanism in which the actuatingparts are substantially enclosed and which thepressure between theknives varies w-ith the-relati-ve move mentof the knives;

It will be obvious that-.-various.changes maybe made by those skilled inthe art inthe details ofthe embodiment of the invention illustrated inthe drawings and described in detail abovewith intheprinciple and scope-of the inventien as expressed in theappended claim.

I claim:

A pinking mechanism for-asewing machine having a base,- stitch-formingmechanism? 1 and operating means for the stitch-forming meche 'anism;which pinking mechanism i-ncludes in combination a frame adapted tobesecured-to mounted on;the frame and having a lv shaped openingtherein, a lever pivotally mounted on the frame and adapted tuberactuated by the operating means for the stitch-forming mechanlsm, aknife carrier pivotally mounted at'i-lone' end of the lever,- a V-sh-aped knife-, carried :by the knife carrier-and positioned-to cooperatewith the ledger blade, stationaryguides engaging. the v-jshaped knife; aleaf'spring securediatonerend of the knife carrier, and an abutment fortheleaf spring spaced away from the knife carrier adis' tancegreaterthan the pivotal axis-.oft'th dever. a "MAXBOPPERJ

